A 2007 expert panel convened by the Eunice Kennedy Shriver National Institute of Child Health and Human Development highlighted the need for more research in the area of fertility among cancer survivors. As survival rates have improved, it has become increasingly apparent that many life-saving cancer therapies impair fertility among childhood cancer survivors. Survivors of young adult cancers are affected as well, but the incidence and prevalence of infertility in this population is unknown. We propose to perform a population-based epidemiology study to characterize the risks of gonadal damage secondary to exposure to chemotherapy and radiation therapy in female survivors of young adult cancers (cancers diagnosed between the ages of 20-39). Eligible cancer survivors will be identified through the award-winning Georgia Center for Cancer Statistics, which operates both the statewide Georgia Comprehensive Cancer Registry and the Metropolitan Atlanta Surveillance Epidemiology and End Results (SEER) Registry of the National Cancer Institute's SEER Program. Reproductive age female survivors of young adult cancers living in Metropolitan Atlanta will be eligible, and their exposure to different cancer treatments will be determined based on abstraction of medical records. We will also recruit a community-based comparison group of women who were not exposed to cancer therapies. Evaluating the incidence and prevalence of infertility is challenging because no single outcome measure truly captures compromised fertility, and subfertility is usually unrecognized until pregnancy is attempted. Therefore, we will evaluate fertility from several angles summarized by two aims. First, we will assess the fertility history of cancer survivors (n=2,000) compared to unexposed women (n=1,000). We will use an in-depth computer assisted telephone interview (CATI) to collect data on a wide range of factors contributing to reproductive potential including, menstrual history, pregnancy history, infertility history, and desire for children. Second, we will assess current fertility of cancer survivors (n=750) compared to unexposed women (n=250) based on a number of clinical markers including anti-M|llerian hormone levels, antral follicle count, ovarian volume, and uterine volume. Our proposal is innovative in several areas. It improves upon existing studies first by being population based in young adult cancer survivors and second by fully capturing the complex nature of fertility by assessing a wide range of indicators of fertility across each woman's reproductive life span and combining this information with measurement of biomarkers of current fertility in a large subset of the population. For young women diagnosed with cancer, the potential effect of different therapies on their ability to have children is often a significant concern, but at present, clinicians have limited information with which to advise them. Our proposal will directly address this critical gap in knowledge.